Inconsistency between `max_length` and `vllm_max_model_len` in official examples

[kyrie-maker]

Description

I noticed an inconsistency in the official examples in https://swift.readthedocs.io/en/latest/Instruction/GRPO.html regarding the relationship between max_length and vllm_max_model_len parameters.

In the official examples (both async mode and colocate mode), these parameters are set differently:

--vllm_max_model_len 8192 \
--max_length 4096 \

Questions

1. Is this inconsistency intentional? If so, what's the rationale behind having different values for these parameters?
2. What are the potential impacts of having different values for these parameters?

Expected Behavior

I would expect these parameters to be consistent since they both relate to sequence length handling. Looking forward to clarification on these parameters.

[hjh0119]

max_length refers to the length of the query (prompt) part, while vllm_max_model_len corresponds to the maximum length of the query + response.